HD 195479

Location of HD 195479 on the map (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	20h 30m 58.26388s[1]
Declination	+20° 36′ 23.0762″[1]
Apparent magnitude (V)	6.20±0.01[2]
Characteristics
Spectral type	kA1 hA9 mF2[3]
U−B color index	+0.13[4]
B−V color index	+0.12[4]
Astrometry
Radial velocity (Rv)	−40.1±1.6[5] km/s
Proper motion (μ)	RA: +95.633 mas/yr[1] Dec.: +58.78 mas/yr[1]
Parallax (π)	11.3074 ± 0.0337 mas[1]
Distance	288.4 ± 0.9 ly (88.4 ± 0.3 pc)
Absolute magnitude (MV)	+1.53[6]
Details
Mass	2.05+0.38 −0.24[7] M☉
Radius	2.15±0.11[8] R☉
Luminosity	38.96+0.36 −0.42[1] L☉
Surface gravity (log g)	4.08[9] cgs
Temperature	8,454[10] K
Metallicity [Fe/H]	−0.11[11] dex
Rotational velocity (v sin i)	18.0±0.6[9] km/s
Age	631[12] Myr
Other designations
AG+20°2271, BD+20°4602, GC 28540, HD 195479, HIP 101213, HR 7839, SAO 88783, CCDM J20310+2036A, WDS J20310+2036A, TIC 379435621[13]
Database references
SIMBAD	data

HD 195479, also designated as HR 7839, is a solitary star located in the northern constellation Delphinus, the dolphin. It has an apparent magnitude of 6.20,^[2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively close at a distance of 288 light-years based on Gaia DR3 parallax measurements^[1] and it is drifting closer with a heliocentric radial velocity of −40.1 km/s.^[5] At its current distance, HD 195479's brightness is diminished by an interstellar extinction of 0.27 magnitudes^[14] and it has an absolute magnitude of +1.53.^[6]

HD 195479 is an Am star with a stellar classification of kA1hA9mF2.^[3] The notion indicates that it has the calcium K-lines of an A1 star, the hydrogen lines of an A9 star, and the metallic lines of a F2 star. It has 2.05 times the mass of the Sun^[7] and 2.15 times the radius of the Sun.^[8] It radiates 38.96 times the luminosity of the Sun^[1] from its photosphere at an effective temperature of 8,454 K,^[10] giving it white hue when viewed in the night sky. HD 195479 is deficient in iron, having an abundance 77.6% of the Sun's.^[11] It is estimated to be 631 million years old^[12] and it spins modestly with a projected rotational velocity of 18.0 km/s,^[9] common for Am stars.

The star has two optical companions: a 12th magnitude star designated B located 5.7" away along a position angle of 88° and a 13th magnitude star designated C located 55.9" away along a position angle of 206°.^[15] They were both observed by American astronomer Sherburne Wesley Burnham during the late 19th century.^[16] B and C are both background stars that are far more distant than HD 195479.^[17][18]